Lubricant and process for preparing and using same



Patented May 29, 1945 LUBRICANT AND PROCESS FOR PREPARING AND USING SAME Maurice Reswick, Wilkinsburg, Pa., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application October 29, 1942, Serial N0. 463,780 I I Claims.

This invention relates to 'a novel lubricant and I to methods of preparing and using same. More particularly. it relates to a metal fabricating lubricant and especially toone which is adapted for lubrication of sheet steel, etc., as it is being processed in high speed cold rolling mills. product of this invention is intended to be used also as a replacement for palm oil which has largely been used heretofore by' the steel mills-for such purposes. p In the cold rolling of steel sheets and strip on when dies and presses are used.

the modern 4-Himills, it isnecessary to use a lubricant to reduce the. friction between the work rolls and the metal. The pressures and temperatures are high and experience has shown that palm oil is, the best lubricant when heavy reductions in gauge are made. is to heat the palm oil in a tank, pump it to the rolling mill stands and apply it to the top and bottom rolls by means of a spray. A characteristic,

of palm oil is that it is a solid or a semi-solid at room. temperatures but when heated to over ,120

F. it becomes a fluid. When sprayed on the watercooled rolls the palm oil congeals and is not washed 016. During the rolling operation it spreads evenly over the surface of rolls, thus providing lubrication over the entire width of the sheet rolled.

The primary object of the present invention is to provide a metalfabricating lubricant which so nearly resembles palm oil in physical and chemical properties that in actual commercial operations in the steelmills where it is vitally -'important to have a high speed sheet steel lubricant having exactly the right combination of viscosity,

lubricity, adhesiveness, and melting point or fluidity that'it will be a completely satisfactory re- 1 oil in commercial steel-rollplacement for palm ing practice.

Another object of this invention is to provide a lubricant which'can also be used satisfactorily for other metal-fabricating processes such as cold drawing of metal, stamping and forming required Broadly, the invention comprises compounding or blending a foots oil, a petrolatum having a melting point of 90 to 130 F., a heavy mineral oil having aviscosity of 100-350 seconds Saybolt at 210 F., a fat such as hydrogenated fish oil, tallow,

etc. and a fatty acid such as hydrogenated fish The The usual procedure acid and oleic acid.

from a paraflinic crude petroleum although oth'er crud es such asnaphthenic or mixed base crudes may be used if necessary. The. heavy mineral oil may bederived from any available crude. Foots oil, which usually contains about 45%50% of wax having a melting point of from 100 to 120, usually'has a-pour point of about 90F.

fish oil such as that marketed under the trade name of Hydrofol Tinfat 50." Other tats or fatty materials which may be used are: degras, animal tallow, hydrogenated vegetable fats, such as of cottonseed oil, etc.

The preferred fatty acid for the purposes of this invention is a hydrogenated fish oil acid such as marketed under the trade name of"Hydrofol Acid 51," although other high molecular weight organic acids, in addition to those mentioned above, may be used such as cottonseed "stearic acid, palmitic acid.

In compounding these various ingredients, it' is of course understood that some variations may be made in'the proportions of materials but generally the compositions selected should be within the following range of. proportions:

30 Foots oil 40 to 60% preferably 45 to 55% 'Petrolatum .5 to 30% preferably 15 to 25% Heavy mineral. oil 5 to 25% preferably -to Fat 5 to preferably 10 to 15% Fatty acid 2 to 20% preferably 5 to 15% oil acids,

cise materials and proportions ing examples are given;

Examples Material I 1 i 2 3 .4 5 6 Foots oil..-

Hydrofol Tinfat; Hydrofol Acid 61". Crude petrolatum Cylinder oil eases see -In the above Examples l and 2 the materials For the sake of illustrationbut withoutintend ing to limit the invention specifically to the 'preused, the'follow oil acids and/or higher fatty acids such as steari'c I vIt is preferred that the roots oil be obtained The preferred fat to be used is a hydrogenated Melting point, A. S. T. M F...

used had the following identifying characteristics:

of a mixture of a low viscosity oil and a low melting point wax. The desirable feature oi. foots oil is that the low viscosity oil is ideal for high speed rolling operations, which now go up as high as 3000 ft. per minute. The wax content of foots oil imparts to the compound a high cold test so that it acts in this respect in the same manner as palm oil.

Hydrofol Tinfat is a hydrogenated fish oil containing less than 20% of acids of 020 to C22, the balance being mostly C18 to Cm, and it is suitable for lubrication at high temperatures. It has a low iodine number and in this respect it is superior to common tallow.

Hydrofol Acid 51 is also a hydrogenated fish oil similar to the Hydrofol Tinfat with the glycerides removed. The purpose of this fatty acid is to Foots oil- Pour point F 70 Wax content (110 M. Pt.) per cent 48 Oil content (80 secs. vis. at 100 F.) per cent 52 Hydrofol Tinfat Melting point f F 130 Saponification value 190 Iodine value Hydrofol Acid 51- Saponification No 194 Acid No 194 Iodine No 6 Titre C 52 Crude petrolatum, melting point F 130 Cylinder oil Vis., Saybolt 100 F seconds 3200 vis., Saybolt 210 F do 155 The finished compounded product identified above as Example 1 had the, following characteristics:

102 solidification point (A. S.T. M, pour) F 95 ,Flash point F 370 Fire'point F 395 Saybolt viscosity at 130 F "seconds" 93 Saybolt viscosity at 210 F do 47 Unworked penetration at 77 F 182 Worked penetration at 77 F 284 Saponification No 40.9 Free fatty acid (as oleic acid) per cent 10.4 Iodine value Both Examples 1 and 2 were used in large scale tests on a 54" cold roll tandem mill where normally steel sheets'are reduced from 0.070" to 0.010" in commercial high speed rolling of sheet steel using rolling speeds such as 1500 to 3000 ft. per minute, and both of these products gave satisfactory results, although the product of Example 2 containing a slightly higher percentage of petrolatum and slightly less cylinder oil was slightly superior to Example 1.

The product of Example 2 was also used successfully on a 5 stand tandem mill, in rolling an extremely tough high-phosphor steel from an initial gauge of .072" to sheets having a finished gauge of .010", 32" wide, and rolled at a speed of 1700 ft. per min,

Undoubtedly the extremely satisfactory results obtained with the metal-fabricating lubricants of this invention are due to the cooperation of the various ingredients with one another to produce precisely the desired balance of physical and chemical properties which is so important and in fact actually critical for rolling sheet steel at such high speeds as those of 1500. ft. per minute and higher. Therefore it is probably impossible to ascribe any one particular characteristic of.

the finished product to one particular ingredient and say that that ingredient is solely responsible for such characteristic. However, in a general way, to assist those skilled in the art in making slight adjustments in the proportions of materials within the general range as indicated above as permissible, the following tentative explanation of the properties and functions of the individual constituents will be-given.

The function of the foots oil as one of the principal components is to act as a vehicle for the other ingredients. Foots oil is a by-product in the manufacture of petroleum waxes and consists Y to actually shear it off.

lower the surface tension of the compound and improve its wetting ability, causing it to spread quickly over the metal surfaces.

The crude petrolatum helps to make the product more adhesive to metal surfaces and both the 'petrolatum and the cylinder oil, such as that marketed under the name Cylesso 155, is used to impart to the compound a homogeneous structure, especially to break up the crystalline or granular structure due to the wax content in the It usually should have a viscosity of about 40-60 seconds, preferably 45-55 seconds Say-bolt at 210 F. It also has good adhesion to the steel rolls and to the sheet metal being rolled. It may be applied to the rolls of a sheet metal rolling mill either by spraying or dripping from one or more suitably spaced tubes soas to provide even distribution of the lubricant throughout the entire .length of the rolls. If desired, it may also be sprayed or run on to the sheet metal itself prior to, during or after rolling. Ordinarily this lubricant is heated to a temperature of about to F. in a suitable supply tank from which it is pumped to the various mill stands, where it may be applied, for instance, to the top and bottom back-up rolls. As the warm liquid lubricant impinges on the relatively cool roll surface, the liquid lubricant loses its fluidity, becoming more viscous and the copious flow of cold water, also usually applied to the rolls, assistsin cooling the lubricant without washing it ofi, so long as the pressure of the water stream is not high enough When the sheet metal such as thin sheet steel actually goes through the work rolls, it becomes coated with the lubricant, but at the same time it is subjected to mechanical working during the reduction in thickness and at the contact area of the work rolls with the sheet strip, the temperature of the strip becomes sufilciently high to change the water into a cloud of steam and to liquefy the lubricant in a thin the thickness gauge at the start and finish of the rolling andhow much reduction is made in each individual pass; the surface finish desired, the

method of application to the rolls and sheet metal, etc. Generally, however, the amount of oil used will be about to lbs. perton of steel strip, generally a relatively small amount being required on the first stand and the largest amount being required on the next to the last stand or the one immediately preceding it. This same lubricant is well adapted for use as a rust inhibitor after the roller sheet steel has gone through the pickling bath to remove oxide scale. It may also be used to cover the molten metal bath during the manufacture of tin plate and terne plate.

In order to avoid waste this metal-fabricating lubricant may be recovered for re-use by a relatively simple system of salvaging and reconditioning. Thisinvolves merely collecting the oil, which is generally mixed with water and perhaps dust and fine iron scaleparticles, in a trench or ture from there, preferably through a %-incl 1 mesh screen, into a settling tank. heating it under slight superatmospheric pressure, if desired toa temperature at least as high as 150 F. and preferably somewhat higher such as 200 and 250 F. in order to settle out the water and coarse foreign particles, and then drawing off the clarified oil. If desired; this clarified oil may be further refined by centrifuging.

I claim:

1. A normally solid lubricant having a melting point between about 90 F. and 140 F., a viscosity of about .40 R160 seconds Saybolt at 210 F., comprising at least 60% by weight of foots oil sump under the cold, roll mills, pumping the mix- I and petrolatum, said lubricant also comprising 2. A normally solid metal-fabricating lubricant having a'melting point between about 90 having a melting point between about 95 F. and about 110 F., a viscosity of about 45 to 55 seconds Saybolt at 210 F. comprising about 40-60% by weight of foots oil, about 15-25% of petrolatum, about 5-25% of heavy mineral .oil having a viscosity of 100 to 300 seconds Saybolt at 210 F., about 5-20% of a'fat and about 2-20% of a higher fatty acid.

' .4. A normally solid metal-fabricating lubricant having a melting point between about 95 F. and about 110 F., a viscosity of about to second Saybolt at 210 F., comprising about 45-55% by weight of foots oil, about 15-25% of petrolatum, about 10-15% of heavy mineral oil having a viscosity of about 100 to 350 seconds Saybolt at 210 F., about 1015% of a fat and about 515% of a higher fatty acid. a

5. Anormally'solid metal-fabricating lubricant having a melting point between about 95 F. and about 110 F.,' adapted for cold rolling of sheet steel at a speed .of at least 1500 feet per minute,

comprising about 45-55% by weight of foots oil having a pour point of about F. to about F. and containing about 45-50% of wax having a melting point' of from F. to .F., said lubricant also containing about 15-25% of petrola'tum having a melting point of about. 90 F. to F., about 10-15% of heavy mineral oil having a viscosity of about 100 to 350 seconds F. and F., a viscosity of about 40 to 60 seconds Saybolt at 210 F., comprising about 40-60% a by weight of foots oil, said lubricant also containing about 10-30% of petrolatum, about 5-25% of heavy mineral oil having a viscosity of about 100 to 350 seconds Saybolt at 210 F., about 5-20% of a fat and about 2-20% of a higher fatty acid.

3. A normally solid metal-fabricating lubricant Saybolt at 210 F., about 1015% of hydrogenatedabout 515% of hydrogenated fish oil having a melting point between about 95 F. and' about 110 F., adapted for cold rolling of sheet steel at a speed of at least 1500 feet per minute, comprising about 50% by weight of foots oil having a pour point of about 70 F. to about 90 F. and-containing about 48% of wax having a melting point of from 100 F. to 120 F., in 52% of an oil having a viscosity of about 80 seconds Saybolt at 100 F., said lubricant also containing about 20% of petrolatum having a melting point of about 90 F. to 130 F., about 10% of a cylinvtier oil having a viscosity of about 3200 seconds Saybolt at 100 F. and about seconds Saybolt at 210 E, about 10% of a hydrogenated fish oil acid.

- 7. Lubricant according to claim 6 in which the hydrogenated fish oil is Hydrofol Tinfat.

8. Lubricant according to claim 6 in which the hydrogenated fish oil acid is Hydrofol Acid 51. 

